Buffer



Feb 7, 1950 E. H. WALTKE 2,496,323

BUFFER Original Filed Dec. 15, 1945 Fignln Patented Feb. 7, 1950 BUFFER Edwin H. Waltke, Los Angeles, Calif.

Original application December 15, 1943, Serial No. 514,359. Divided and this application June 20, 1946, Serial No. 677,949

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) Claims.

The invention described herein may be manu- This invention relates to improvements in buffers, for absorbing the shock of recoilmovement of the breech block in a machine gun, and represents a division of my application Serial No. 514,359 for Multpile barrel machine gun, filed December 15, 1943 and now Patent Number 2,410,848 dated November 12, 1946.

An object of the invention is to provide a bufier containing a fluid, such as air or gas, under pressure.

Another object of the invention is to provide a piston, in contact with the fluid and protruding into the path of a breech block, whereby the fluid is further compressed to check the breech block travel and initiate a, counter-recoil movement thereof.

A further object of the invention is to provide a. valve for filling the fluid chamber to any deiired pressure, and replenishing such pressure lost inder working conditions.

A still further object of the invention is to proride a buifer of simple and sturdy construction 'rhat Will withstand the severe pressures inflicted ipon it during operation of the gun.

Other objects and advantages of the inven- ;ion will be apparent during the course of the followin description.

In the accompanying drawings, forming a part if this specification, and in which like numerals LIG employed to designate like parts throughout he same,

Figure 1 is a fragmentary longitudinal sectional iew of the rear end of a machine gun receiver, howing my buffer attached thereto, and,

Figure 2 is a transverse sectional view of the uffer.

Heretofore it has been the practice to provide reech block bufiers with flexible backing in the orm of rubber blocks, springs, spring washers or ii dash pots, all of which are subject to deteri-ora ion and therefore require frequent disassembly f the bufier for replacement. Adjustment, if ny, to working pressures is slight.

The present invention contemplates the use f fewer and sturdier parts, backed by a more .exible means, in the form of air or gas, into.

'hich power in stored by the recoiling breech lock for a quick recovery into a counter-recoilig force.

In the event of any pressure loss, the cylinder lay be quickly recharged with pressure from an how 69 entering into a counter bore 15.

outside source, which can be connected after the removal of the filling plug.

Referring now to the drawings, wherein for the purpose of illustration, a preferred embodi- 'ment of my invention is shown, the numeral l designates a portion of a machine gun receiver.

A breech block 23 is slidably mounted in the receiver and is driven in recoil and counter-recoil by any well known means, (not shown), or as shown in my patent hereinbefore identified.

The rear end of the receiver is closed by a plate 63. The plate is formed with a screw-threaded opening for attachment of a bufier which will now be described.

A single bufier cylinder 68 is provided with an externally screw-threaded portion for engagement with the threaded opening in the plate 63, and extends rearwardly therefrom. Centrally of its forward end the cylinder is provided with a The counter bore 15 forms a chamber for the fluid under pressure. These bores are concentric to each other and form a shoulder or seat 16 at their junction.

Slidable in the bore 69 is a stepped buffer piston 10, said piston having portion snugly but slidably fitting within the bore 69 and counterbore 15 and forming a stop or shoulder 11 shaped to effect a gas tight abutment with the shoulder 16 of the cylinder.

A screw plug 14 is threaded into the rear end of the cylinder 68 and has formed therein an orifice l3, closed at its outer end by a filling plu 14', said orifice being formed with a valve seat 18 at its forward end for receiving a ball valve 12.

The ball valve 12 is held in alignment with its seat 18 by a rod 1| secured thereto and ex tending forwardly and into a central bore 19 formed in the piston 10. A spring 14', surrounding the rod 1! and interposed between the slidable piston 10 and the ball valve 12, holds the ball against its seat 18 to close the orifice l3, and also forces the piston shoulder 11 against its seat 16. Air or gas, is confined in the bufier cylinder, introduced therein through the orifice 13, which is available for the introduction of such fluid upon removal of the threaded filling plug 14''.

The filling plug 14" is formed on its inner face with a frustro-conical extension whose inner end is concentric with the orifice 13, and is intended to seal the outer end of the orifice. This seal may be dispensed with if working pressures do not demand it.

In order to insure gas tight contact between the tained pressure in the cylinder, effects the bufiing,

of the block. The increased pressure in the cylinder will initiate the counter recoil strokeaof1'the? block.

In use the buffer can be completely assembled and attached to the receiver of the gum-Mandate any convenient time the cylinder may be charged to the required pressure. This-charging-'isac=- complished by simply removing thefilling' plug 14" and attaching a pressure line to the screw plug'l i; whereupon the valve. 'IZ'rwill :be unseated and pressure will be admitted? to' the bore 15. Likewise if the;pressureis-reduced belowaworkable degree, due to continued'use or'disuse, the operation can berepeated: without disassembly or removal of the buiferfrom the gun:

It is to be understood that'the form ofmy invention, herewith shown and described; is to betaken as a preferred example of the" same, and that various changes in the shape, size and arrangement of parts may be resorted to; without departing from the spirit of my invention, as defined by the subjoined claims.

Having thus described my invention; I claim:

1. A buffer structure comprising, a hollow-cylinder for the reception of a compressedLgas: and having a slidable piston fitting gas tighttherein, said piston having-a centrally disposed seat in" its inner face; stop shoulders inthe cylinder'and on the piston for limiting the outward movement of the-piston, an'aperturedplug at the other end of the cylinder, a valve seated insaid" aperture, said valve having a stem secured thereto. andex tending forward into the centrally disposed: seat in the piston, and aspring surrounding-said valve stem for normally seating the-valve and the slidable piston;

21 Ina buffer structure, the=combinationwith a-machine gun having a receiver andiazreciproreating breech block of a hollow-'gas'filledcylinder secured to the receiver'in' line with thevpath of travel of the breech block; a'slidable pistonzfitting gas-tight in one end of thecylinder, .stopzshoulders inithercylinder and on'the piston forengagement with each other to limit the outward movement of the piston, said piston having a centrally disposed seat in its inner-face, an apertured'closure plugatthe other. end of the cylinder; a valve seatediin the aperture, said valve having, a stem secured thereto: and extending forward-into the centrally disposed seat in the piston, and a'spring surrounding'said" valve stem for exertingits pressure to. normally seat the: valve and projectthe piston. outwardly of the. cylinder and intorthe path of :thereciprocating breech block..

3; A bufier'guni structure for a gunihavinga receiver and, a breechblock.reciprocablectherein, a cylinder securedinthe rear wallof thereceiver with'the forward-end .of its bore opening into said receiver, a piston: reciprocable. in said cylinder and. having a central axial bore opening through the rear face thereof, a screw-plug closing the rear end of said cylinder and having an axially extending passageway, the forward end of said passageway forming a Valve, seat, and a valve in saidicylinder to engageesaid seat to close said passageway, said valve including a stem having its forward end slidably fitting the bore in said piston.

4. A buffer for a machine gun having a receiver with-.arear wall and a breechblock reciprocable therein, a cylinder secured in the rear wall with itszforwardwnd; opening therethrough, a piston slidable in said: cylinder said piston having a central axial boreopening through the rear face thereof, means limiting forward movement 01 said piston to a position in which the forward end thereofi'is engagediand moved rearwardly by the breechblock: during the final portion only of it: rearward reciprocation; a screw plug closing the rear end of,said cylinder; there being an axia. passageway through saidv screwplug: having its forwardend shaped 'to form ;a -:valve seat, a 1 valvt in said cylinder adapted to. engagesaid seat, saic valve; including a stem slidablye-ngaging the borr insa-id'piston, and atcoi-lspring surrounding saic stern-and bearing at-oneend -on said valve and'a' the other end onsaid piston, said stem limiting the rearward reciprocation ,of'the piston? in 17111 cylinder.

5. In a buffer structureifor a gun havingare ceiver. with a; rear; wall, acylinderthreaded. intr anaperture in said'wall and having, the-bore. 11 its forward end of reduced diameter to formzz circumferentia'lly-extendingrearwardly-facin; shoulder, a-'stepped'-piston' havingyportions of dif ferentdi-ameters each fittingga respective portioi of said-cylinder; said step engagingsaid shou'lde to limit the? forwardmovement of said piston 11 said cylinder, there being an axial bore-in sai1 piston openingythrough :the-rear face thereof, plug closing-'therrear end ro-fisaid' cylinder,- ther being;v a-gas passage in said, plug having itsfor ward end within said cylinder formed as a: valv seat, a valve acomprisingta ball .in saidcylinder t engagesaid seatand close said passage, a radie stemextending from saidlball and slidably fittin the bore in saidpistonto'limit therearwarl movement thereof, and/alcoil spring on said ster urging theball ontosaid seatand the piston int forwardmost position.

EDWIN I-I. WALTKE.

REFERENCES; CITED The following references are of record'in th file of this patent:

UNITED STATES PATENTS Number Name Date 1,037,730 Cowey Sept. 3, 191 1,297,240 Pritchett Mar. 11, 191 1,680,890 Laugaudin' Aug. 14, 192 1,749,137 Hudson; n .Mar. 4, 193

1,772,387 Dickerson1 .Aug. 5,193 1,955,349 Sproul Apr. 17, 193 2,089,657 Mercier:: Aug. 10, 193

FOREIGN PATENTS Number" Country Date 752,886 France: July 31, 192 

